Unsaturated melamine condensates

Abstract

An unsaturated condensate of an alkoxymethylmelamine, an allylic alcohol and an acrylamide wherein the alkoxymethyl group contains from 1 to 4 carbon atoms, wherein the ratio of allylic moieties to acrylamide moieties is in the range of about 3:1 to about 1:3, wherein there is at least about 0.75 allylic moieties and no more than about 3 acrylamide moieties per melamine ring and wherein the total of allylic moieties and acrylamide moieties is in the range of about 2 to about 4 per melamine ring. The unsaturated condensates are used in high solids unsaturated coating systems containing unsaturated oil-modified resins.

What is claimed is: 
     
       1. An unsaturated condensate of an alkoxymethylmelamine, an allylic alcohol, and an acrylamide, wherein the alkoxymethylmelamine has a combined ratio of formaldehyde to melamine in the range of about 5:1 to about 6:1 and a combined ratio of etherifying alcohol to melamine in the range of about 4.7:1 to about 6:1, wherein the alkoxymethyl groups of the unsaturated condensate contain C 1  to C 10  alkoxy groups, wherein the acrylamide is represented by the formula: ##STR3## wherein R 1  and R 2  are selected from the group consisting of hydrogen and methyl, wherein the allyl alcohol is represented by the formula: ##STR4## wherein R 3  is hydrogen or a C 1  to C 4  alkyl group, wherein the ratio of allylic alcohol moieties to acrylamide moieties in the condensate is in the range of about 3:1 to about 1:3, wherein the condensate contains at least about 0.75 allylic moieties and no more than about 3 acrylamide moieties per melamine ring and wherein the total of allylic moieties and acrylamide moieties of the condensate is in the range of about 2 to about 4 per melamine ring. 
     
     
       2. The unsaturated condensate of claim 1, wherein the alkoxymethylmelamine is methoxymethylmelamine. 
     
     
       3. The unsaturated condensate of claims 1 or 2, wherein the allylic alcohol is allyl alcohol or methallyl alcohol. 
     
     
       4. The unsaturated condensate of claims 1 or 2, wherein the allylic alcohol is allyl alcohol. 
     
     
       5. The unsaturated condensate of claims 3 or 4, wherein R 1  and R 2  are hydrogen. 
     
     
       6. The unsaturated condensate of claim 1 wherein the condensate contains about 1 to about 3 allyl groups and from about 1 to about 2 acrylamido groups per melamine ring. 
     
     
       7. The unsaturated condensate of claim 6, wherein the alkoxymethylmelamine is a methoxymethylmelamine. 
     
     
       8. The unsaturated condensate of claim 1 wherein the condensate contains about 1.5 to about 2.5 allyl moieties and about 1 to about 2 acrylamide moieties per melamine ring. 
     
     
       9. The unsaturated condensate of claim 8, wherein the alkoxymethylmelamine is a methoxymethylmelamine. 
     
     
       10. A process for the preparation of an unsaturated condensate of an alkoxymethylmelamine, an allylic alcohol, and an acrylamide which comprises reacting the acrylamide with the alkoxymethylmelamine at a temperature below about 120° C. until the reaction is substantially complete and reacting the acrylamide--alkoxymethylmelamine condensate with the allylic alcohol at a temperature in the range of about 80° to about 110° C. in the presence of a catalytic quantity of an acid catalyst and a polymerization-inhibiting quantity of an inhibitor, wherein the alkoxymethylmelamine has a combined ratio of formaldehyde to melamine in the range of about 5:1 to about 6:1 and a combined ratio of etherifying alcohol to melamine in the range of about 4.7:1 to about 6:1, wherein the alkoxymethyl groups of the unsaturated condensate contain C 1  to C 10  alkoxy groups, wherein the acrylamide is represented by the formula: ##STR5## wherein R 1  and R 2  are selected from the group consisting of hydrogen and methyl, wherein the allyl alcohol is represented by the formula: ##STR6## wherein R 3  is hydrogen or a C 1  to C 4  alkyl group, and wherein the condensate has a ratio of allylic moieties to acrylamide moieties in the range of about 3:1 to about 1:3, the total of allylic moieties and acrylamide moieties being in the range of about 2 to about 4.0 per melamine ring, at least 0.75 being allylic moieties and not more than 3 being acrylamide moieties. 
     
     
       11. The process of claim 10 wherein the alkoxymethylmelamine is a methoxymethylmelamine, the allylic alcohol is allyl alcohol and the acrylamide is acrylamide. 
     
     
       12. The process of claims 10 or 11, wherein the catalyst is an acid of pKa less than about 3.